In pictures: Norfolk fatal US helicopter crash at Cley

8 January 2014
Last updated at 14:55

An investigation is under way into what caused a US Air Force helicopter to crash in Norfolk during a low-level training mission killing all four people on board.

Investigations have started into what caused a US Air Force helicopter to crash in Norfolk, killing all four people on board. The HH-60G Pave Hawk, from RAF Lakenheath, Suffolk, came down at Cley next the Sea on Tuesday night.

The aircraft, assigned to the 48th Fighter Wing, was on a low-level training mission. Debris from the crash "on difficult terrain in the marsh" is spread over an area "about the size of a football field", said Norfolk Police.

The military helicopter came down at a nature reserve in Cley next the Sea. An area is cordoned off and the A149 through Cley is closed. Members of the public are urged to avoid the area.

The investigation into Tuesday night's Pave Hawk crash is being hampered by the fact it was carrying munitions. Norfolk Police said they were investigating the nature of the weaponry, which may pose a risk to the public.

A second helicopter from RAF Lakenheath was also in the area at the time of the crash and sent to the marshes to try to assist - it remains at the scene while the investigation continues.

Military aviation analyst Roger Smith said he was "very surprised" this type of helicopter was involved in a crash. Details of the four crew members will not be released until next-of-kin have been informed, police said.

The 48th Fighter Wing, also known as the Liberty Wing, is assigned to the United States Air Forces in Europe. In addition to HH-60G Pave Hawks, it is home to squadrons of F-15 Eagle tactical fighter planes and F-15E Strike Eagle dual-role fighters.

Equipment arrived on American transporters at Cley next the Sea in north Norfolk as military personnel and emergency services attended the scene of the Pave Hawk helicopter crash.

Police have formed a cordon in the village of Salthouse as military personnel and emergency services conduct their investigations, it is expected to last throughout Wednesday.